The fluorescent treponemal antibody test for cerebrospinal fluid (FTA-CSF) using monospecific conjugates
anti-IgG,
IgM, and
IgA was used to determine the presence of anti-treponemal
antibodies in the spinal fluid of 335 patients with primary, secondary, and
latent syphilis and symptomatic and asymptomatic
neurosyphilis and of patients with certain
neurological disorders. Of these, 230 (68·65%) patients had non-reactive results to this test. Of the remaining 105 patients, 78, 63, and 10 had reactive results with
anti-IgG,
IgM, and
IgA conjugates respectively. Of the 129 cases of known
syphilis, 11 were diagnosed as primary, 32 as secondary, and 50 as latent, and 36 patients had
neurosyphilis. None of the specimens from the patients with
primary syphilis gave reactive results to the test. Specimens from 21 (65·62%) of the 32 patients with
secondary syphilis, 30 (60%) of the 50 patients with
latent syphilis, and all (97·22%), except one, of the 36 patients with
neurosyphilis gave reactive results to one at least of the
IgG,
IgM, or
IgA FTA-CSF tests. Among the specimens from patients with
secondary syphilis twice as many gave reactive results with
anti-IgG conjugate than with
anti-IgM conjugate. However, with specimens from patients with
latent syphilis and
neurosyphilis this ratio was diminished to 1·5:1. The Kolmer
complement-fixation test, although superior in sensitivity and specificity to the
Venereal Disease Research Laboratory (VDRL) test, in patients with secondary and
latent syphilis and
neurosyphilis, was greatly inferior to the FTA-CSF test. Data indicate that anti-treponemal
antibodies can be detected in the spinal fluid even in patients with no neurological symptoms in cases of
secondary syphilis and that the FTA-CSF test can be a valuable tool in the early detection of an immunological response to
treponemal infection in the spinal fluid.